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Should I buy mercury UV lamps?

Time: 2020-06-19

Mercury UV lamps are admired by the general public for the low cost and high power. They are the historic, high-potency discharge lamps in existence and their applications are very common on industrial and commercial level.


Although now, the market of mercury UV lamps are becoming shared by other lamps, they are still considered as one of the most reliable forms of lighting even after the decrease in their popularity.


Mercury UV lamps are widely used in applications where sufficient lighting energy is required. Their essential use is in parking lots and other such enormous-range outdoor lighting applications, such as parks and sports grounds, etc. They are also used as ceiling lights in industries, warehouses, and gyms.

 

Mercury UV lamps

 

However, they are somehow not so good for humans and their health, and excessive utilization of UV mercury lamps can even have life-threatening effects. Mercury UV lamps are hazardous to humans because of the following reasons:


1. Mercury UV Lamps contain mercury


Up to now, nearly all mercury UV lamps generate radiation by means of a gas discharge. Among the most efficient UV radiators are low-pressure mercury UV lamps, which has the highest UV radiant efficiency in air. 


However, low-pressure mercury UV lamps are filled with larger amounts of mercury and often also with certain dopants. Conventional UV Mercury lamps hold their mercury in a liquid form, which have the highest potential to be hazardous both during operation and when the lamp is off. 


Harm of mercury UV lamps


We all know and understand that the exposure to a certain level of mercury can always cause more troubles for skin burns and sometimes visions, even the presence of very low quantity can cause consequences, not to mention that there is no safe vulnerability level for mercury in humans.

 

When combined with several other compounds, mercury has a wide range of acute health effects, including harm to the nervous system, thyroid, kidneys, lungs, immune system, and gums. Victims may even encounter memory loss or language impairment and the damage to the brain cannot be overturned.

 

Minamata disease is a neurological disorder caused by intense mercury contamination. In the most instances, insanity, paralysis, coma, and death follow within a few weeks of the occurrence of the first symptom. Therefore, according to the Minamata Convention on Mercury, China will not produce and sell such lamps since 2021.


Convention on mercury UV lamps


2. Mercury UV Lamps induce Ozone


The low-pressure mercury UV lamps are an efficient ultraviolet light source, usually called germicidal lamps.


If you ever observed it carefully, you will find that in addition to 254nm that can actually kill viruses and bacterial, the light source of the low-pressure mercury UV lamps also have a wavelength of 185nm, which can change O2 in the outside air to O3 (Ozone). 


Ozone is a non-long active molecule, and it' easy to react with other molecules, causing re-decomposition and conversion into oxygen to achieve the purpose of renewing air and deodorizing and sterilizing.


Ozone harm of mercury UV lamps


However, Ozone germicidal UV lamps are not recommended when there are human activities fpr the reason that Ozone in the air will promote the coagulation of hemoglobin after being inhaled into the body, resulting in insufficient oxygen supply to the human body, dizziness and nausea affect health. Especially when the concentration reaches is more than 0. At 3 PPM (Mg/m2) working in an environment will cause serious harm. 


Apart from Ozone, some bulbs of UV mercury lamps emit UVB rays, hazardous for human health and can cause skin and eye injuries.


3. Mercury UV Lamps waste much energy


1. Heat Energy wasted by mercury UV lamps


Compared to UV LEDs, conventional mercury UV lamps direct heat into a small patch and produce a substantial amount of heat immediately, and then transferred the heat energy to the flow of air or water, which leads to elevated heat and even quartz sleeve fouling. 


Also, conventional mercury UV lamps are far more temperature-sensitive making them less effective in non-ideal circumstances. They need to be operated at very high temperatures (850 to 950 Celsius or 1550 to 1750 Fahrenheit). If the lamps run too cool, they may not operate, so we need to keep them on at all times, wasting a great amount of energy.


In contrast, UV LEDs will not transfer heat energy into the air or water, thus reducing fouling rates and ensuring the constant UV output regardless of the temperature.


 Comparison of mercury UV lamps


2. Preheat Energy wasted by mercury UV lamps 

 

Mercury UV lamps also need a long start-up time, that is, an extreme warm-up duration of 5 to 7 minutes before giving full light output, and 4 to 5 minutes in cooling and restarting after the warm-up. Pay attention that the delay in the light emission is hardly acceptable in some applications. 


Meanwhile, these lamps have dreadful lumen maintenance in contrast with the other high intensity discharge (HID) sources, with a power in the 25 to 55 lumens per watt range. 


Extreme supervision is required to keep the supply of the voltage within ±5% of the evaluated voltage value because UV mercury lamps are totally voltage sensitive.UV mercury lamps may be tremendously affected by lamp lumen reduction and should be replaced after 24,000 hours.Few UV mercury lamps have the lifespan of 40 years.


4. Mercury UV Lamps have high recycling cost


Mercury UV lamps are not the premier choice even from a business point of view. They are not environment friendly because of high amount of mercury, which complicates the dumping process.


The companies in some countries are required to recycle the mercury in the lamps otherwise heavy fines are imposed by the governments. For them, the recycling procedure is fully managed and the load for the recycling process is on the lamp distributor who can impose the customer an additional cost per lamp. 


Recycle of mercury UV lamps

 

All in all, UV Mercury Lamps should not be used in any fixture or application that was not designed specifically to prevent exposure to humans or animals. The better applications for UV Mercury Lamps are industries level, such as sports ground and factories.


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